Outraged families on Saturday blasted city officials for placing the unidentified remains of 9/11 victims in an underground repository at the National September 11 Memorial Museum.

About a dozen protesters covered their mouths with black gags to symbolize their voices have not been heard.

“We should have a say as to where the remains should be placed,” said Eileen Walsh, 71, of Sunnyside, Queens. “They belong to us.”

Walsh’s son, Firefighter Michael E. Brennan, was one of 343 Bravest to die at the World Trade Center.

The remains of 1,115 of the 2,753 people killed in the 2001 attacks have yet to be identified, according to the city Medical Examiner’s Office. And of the nearly 22,000 human fragments recovered at Ground Zero, 37 percent haven’t been matched to victims.

One of the two reflecting pools at the National September 11 Memorial.Photo: AP

City experts hope that technological advances in the future will lead to the eventual identification of the remains so they can be turned over to relatives.

Until then, about 7,900 bags of unidentified fragments will be stored in the museum repository 70 feet below ground.

The place will be hidden from public view and be open only to family members and the medical examiner’s staff, who will continue working on further testing of the remains as needed.

Family members of victims can enter the museum for free, while the general public will fork over a $24 admission fee.

But some families want the remains above ground in the plaza, or in a proper tomb or memorial, “not 70 feet below ground,” Walsh told The Post.

On Saturday, a police motorcade led the transport of the remains — placed in three flag-draped caskets carried by a fire truck — on the five-mile trip from the Office of the Chief Medical
Examiner, on the East Side, to their new downtown home.

Police officers and firefighters in dress blues carried the caskets to their resting place inside the museum.

The solemn procession, viewed by about 200 guests including the protesting family members, was devoid of speeches or prayers.

“They have no right to do this. They never asked for our permission. This is a slap in the face,” she fumed to reporters. “This is not a cemetery. It just tears you. They stick the knife in and they twist it.”

Sally Regenhard’s firefighter son, Christian, also died on 9/11.

“We’re out here because we want a proper memorialization of the dead. We are here because it’s an atrocity to put human remains of heroes and victims in a museum,” she said. “We want the mayor to survey the families to see if they agree with this plan.”

Probie firefighter Christopher Santora, 23, was with Engine 54 when he perished on 9/11.

“I’m here to witness the City of New York putting unidentified human remains into a museum,” said Santora’s mother, Maureen. “It’s repulsive.”